Lead-free primary explosives

ABSTRACT

Lead-free primary explosives of the formula (cat) Y [M II (T) X (H 2 O) 6-X ] Z , where T is  5 -nitrotetrazolate, and syntheses thereof are described. Substantially stoichiometric equivalents of the reactants lead to high yields of pure compositions thereby avoiding dangerous purification steps.

RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional Application No.60/800,678, filed May 15, 2006.

STATEMENT OF FEDERAL RIGHTS

The United States government has rights in this invention pursuant toContract No. DE-AC52-06NA25396 between the United States Department ofEnergy and Los Alamos National Security, LLC for the operation of LosAlamos National Laboratory.

FIELD OF INVENTION

The present invention relates to lead-free primary explosives.

BACKGROUND

Primary explosives are used in small quantities to generate a detonationwave when subjected to a flame, heat, impact, electric spark, orfriction. Detonation of the primary explosive initiates the secondarybooster, main-charge explosive, or propellant.

Toxic mercury fulminate, lead azide, and lead styphnate are three commonprimary explosives, but their deleterious environmental impacts andeffects on human health have made their replacement essential. Countlessnumbers of energetic compounds have been designed and screened aspossible primaries, including organic compounds, organic salts,zwitterions, simple organic salts, coordination complexes, andmetastable interstitial composites, but none have simultaneously met thesix criteria for green primaries: (i) insensitive to moisture and light;(ii) sensitive to initiation but not too sensitive to handle andtransport; (iii) thermally stable to at least 200° C.; (iv) chemicallystable for extended periods; (v) devoid of toxic metals such as lead,mercury, silver, barium, or antimony; and (vi) free of perchlorate.Thus, a need remains for environmentally friendly, or green, primaryexplosives.

SUMMARY OF THE INVENTION

The present invention discloses novel lead-free compounds. Moreparticularly, the present invention is directed to compounds of theformula (cat)_(Y)[M^(II)(T)_(X)(H₂O)_(6-X)]_(Z) wherein

-   -   cat is a cation independently selected from the group consisting        of        -   (a) alkali metals,        -   (b) alkaline earth metals,        -   (c) aliphatic and catenated high-nitrogen cations, and        -   (d) heterocyclic nitrogen cations;    -   M^(II) is a metal in the oxidation state plus-two independently        selected from the group consisting of        -   (a) cobalt,        -   (b) copper,        -   (c) iron,        -   (d) manganese,        -   (e) nickel, and        -   (f) zinc;    -   T is the ligand 5-nitrotetrazolate (“NT”); and    -   X is an integer from 3 to 6;    -   Y is an integer from 1 to 4; and    -   Z is an integer from 1 to 2.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows representative cations.

FIG. 2 shows 5-nitrotetrazolate.

FIG. 3 shows 5-nitrotetrazolato-N²-ferrate coordination complex anions.

FIG. 4 shows six embodiments of the novel lead-free compounds.

DETAILED DESCRIPTION

The present invention discloses novel lead-free compounds. Moreparticularly, the present invention is directed to compounds of theformula (cat)_(Y)[M^(II)(T)_(X)(H₂O)_(6-X)]_(Z) wherein

-   -   cat is a cation independently selected from the group consisting        of        -   (a) alkali metals,        -   (b) alkaline earth metals,        -   (c) aliphatic and catenated high-nitrogen cations, and        -   (d) heterocyclic nitrogen cations;    -   M^(II) is a metal in the oxidation state plus-two independently        selected from the group consisting of        -   (a) cobalt,        -   (b) copper,        -   (c) iron,        -   (d) manganese,        -   (e) nickel, and        -   (f) zinc;    -   T is the ligand 5-nitrotetrazolate (“NT”); and    -   X is an integer from 3 to 6;    -   Y is an integer from 1 to 4; and    -   Z is an integer from 1 to 2.

The novel compounds may be prepared from numerous cations includingalkali, alkaline earth, aliphatic and heterocyclic nitrogen compounds(see Huynh et al, Proc. Natl. Acad. Sci. USA 2006, 103(14), 5409-5412;Huynh et al, (2005) J. Am. Chem. Soc. 127, 12537-12543), and theircatenated derivatives (see Huynh et al, Proc. Natl. Acad. Sci. USA 2006,103(27), 10322-10327). Alkali metals comprise Group I of the periodictable and include lithium, sodium, potassium, rubidium, cesium, andfrancium. Alkaline earth metals comprise Group II of the periodic tableand include beryllium, magnesium, calcium, strontium, barium, andradium. Aliphatic and catenated high-nitrogen cations include, but arenot limited to, triaminoguanidinium (TAG⁺), hydrazinium (Hz⁺),nitrosocyanaminium (NCAm) (see Huynh et al, (2001) Agnew. Chem. Int. Ed.40, 3037-3039), ammonium (NH₄ ⁺), and hydrazonium (Hyzm) and otherslisted in Huynh et al (2005; cited above). Heterocyclic nitrogen cationsinclude, but are not limited to, 3,3-dinitroazetidinium (DNA⁺),1,2,5-triamino-1,2,3-triazolium (TATm) (see Drake et al, (2005)Propellants Explos. Pyrotech. 30, 329-337),5-amino-1-nitroso-1,2,3,4-tetrazolium (ANTm) (see Huynh et al, (2001) J.Am. Chem. Soc. 123, 9170-9171), 3,6-bis(guanidinium)-1,2,4,5-tetrazine(BGTZ²⁺), 3,6-bis(nitroguanidinium-1,2,4,5-tetrazine (BNGTZ²⁺), and3,6-bis(hydrazinium)-1,2,4,5-tetrazine (BHzTZ²⁺). FIG. 1 showsrepresentative cations.

The stability exhibited by transition metal primaries depends on theoxidation state of the metal, geometrical arrangement of ligands aroundthe metal, and stereoelectronic (steric and electronic) effects of theligands. Taking these factors into account, the novel compounds may beprepared from numerous transition metals with the oxidation stateplus-two including, but not limited to, cobalt, copper, iron, manganese,nickel, and zinc.

The ligand must provide oxygen content and sensitivity to the metalcomplex anions. Therefore, the novel compounds may be prepared fromoxygen-rich, sensitive, secondary high explosive anions. Mono- anddi-substituted anions of tetrazole and di-substituted anions of triazoleare favorable N-ligands for transition metals. Examples include, but arenot limited to, 5-nitrotetrazolate (“NT”) (shown in FIG. 2) and1-amino-5-nitrotetrazole. Comparison of 1-amino-5 nitrotetrazole to5-nitrotetrazolate reveals the latter to be the more energetic ligandbecause of its more positive oxygen balance (OB_(CO)) and higher energycontent. Moreover, compared with all other heterocyclic five- andsix-member rings, the 5-nitrotetrazolate has a much higher potentialenergy content because of the tetrazole backbone and the nitro group.

Given six ligands around a metal center with the oxidation state oftwo-plus, four different coordinated anions can be assembled, namely[M^(II)(T)₃(H₂O)₃]⁻, [M^(II)(T)₄(H₂O)₂]²⁻, [M^(II)(T)₅(H₂O)]³⁻, and[M^(II)(T)₆]⁴⁻. FIG. 3 shows representative 5-Nitrotetrazolato-N²-ferrate coordination complex anions. Each of thesecoordinated anions can be charged balance by the cations listed in[0012]. For example, if the cation is calcium, then the abovecoordinated anions are charged balanced to produce the followingcompounds: Ca[M^(II)(T)₃(H₂O)₃]₂, Ca[M^(II)(T)₄(H₂O)₂],Ca₃[M^(II)(T)₅(H₂O)]₂, and Ca₂[M^(II)(T)₆].

In these coordination complex primaries, the coordination complex anionsare the primary oxygen carrier as well as the sensitivity bearer whereastheir cationic partners allow sensitivities (friction, impact, andflame) to be fine-tuned for various applications.

Because the (cat)_(Y)[M^(II)(T)_(X)(H₂O)_(6-X)]_(Z) architecturesatisfies all six criteria for green primaries, the compounds can beused as green primary explosives. The compounds are insensitive to sparkeven when dry. When wet by common organic solvents or water, they becomeinsensitive to friction and impact and have no response to an openflame. This ease of desensitization makes them safe to prepare, store,handle, and transport. Before use, they are air-dried at roomtemperature. These compounds are sparingly soluble in most commonorganic solvents and water, structurally stable to light and moisture,and thermally stable to at least 200° C.

The novel compounds can be prepared by refluxing a chosen quantity ofthe metal salt and the desired salt of 5-nitrotetrazolate in a suitablesolvent until the solution mixture becomes clear. Water is a suitablesolvent for [M^(II)(T)₃(H₂O)₃]⁻ and [M^(II)(T)₄(H₂O)₂]²⁻, and absoluteethyl alcohol is a suitable solvent for [M^(II)(T)₅(H₂O)]³⁻ and[M^(II)(T)₆]⁴⁻. Upon cooling to room temperature with gentle stirring,the desired primary quantitatively precipitates leaving behind thecolorless mother liquor. The product is filtered, washed thoroughly withfresh solvent, and air-dried.

Dangerous purification steps can be avoided by employing stoichiometricequivalents of the reactants to form a nearly quantitative singleproduct. An excess quantity of any reactant might result in impurities.

Reference is now made in detail to various embodiments of the compounds.FIG. 4 shows possible configurations for six embodiments including(NH₄)₃[Fe^(II)(NT)₅(H₂O)], (NH₄)₄[Fe^(II)(NT)₆], Na[Fe^(II)(NT)₃(H₂O)₃],Na₂[Fe^(II)(NT)₄(H₂O)₂], Na₃[Fe^(II)(NT)₅(H₂O)], and Na₄[Fe^(II)(NT)₆].

Property measurements were taken for each compound. The density of thecompound was determined using a solid pycnometry technique. The thermaldecomposition temperature of the compound was determined using aDifferential Scanning Calorimetry Exotherm performed with the rate of 5°C./minute.

Sensitivity measurements were taken for each compound. The impactsensitivity for the compound was measured by using a drop-weight machinetype 12 test. Impact sensitivity is an average height in centimeters atwhich a 2.5 kilogram (“kg”) is dropped onto a 40 milligram (“mg”) sampleof an explosive on 150-grit garnet sandpaper. The sample detonated if asound level of 120 dB recorded from a microphone set 33 inches from thepoint of initiations. The test results are summarized as the height incentimeters (“cm”) at which the probability of explosion is 50%.

Friction sensitivity was determined by mini BAM (with capability ofmeasuring from 0 to 1000 grams (“g”)) and BAM (with capability ofmeasuring from 0.5 to 36 kg machines (Reichel & Partner, Rheinazbern,Germany). In each test, a rounded porcelain striker ground to set off 1mg of explosive on a porcelain plate that is mechanically drivendirectly underneath the striker at a given weight. The striker waspivotal to a calibrated arm on which different weights can be hung. Thecriterion for detonation was an audible or visual reaction, or both,recognized by an operator. The test results are statistically reportedas a 50% load with the explosive probability of 50%.

Spark sensitivity from 0 to 6 joules (“J”) was measured by an ABLelectrostatic discharge apparatus (Safety Management Services, WestJordan, Utah) connected to a diagnostic analyzer to detect NO_(X), CO (0to 5,000 parts per million (“ppm”)), and CO₂ (0 to 1,000 ppm) releasedfrom a detonated sample. In an insulating plastic disk sat on aconductive steel base, a 2-to-3 mg sample was covered with a piece ofScotch tape™ (3M Co.), and the assembly was centralized beneath a brassneedle that would be charged when the instrument was initiated. Thischarged needle pierced through the Scotch tape™, discharging the sparkto set off the sample. The spark energy of the explosive sample was sentto the analyzer and recorded in joules.

EXAMPLE 1 Preparation of (NH₄)[Fe^(II)(NT)₃(H₂O)₃]

An iron compound was prepared in accordance with the reaction[Fe(H₂O)₆](ClO₄)₂+3 NH₄NT→NH₄[Fe(NT)₃(H₂O)₃]+2 NH₄ClO₄ or FeCl₂●4H₂O+3NH₄NT→NH₄[Fe(NT)₃(H₂O)₃]+2 NH₄Cl by mixing a solution of 1.00 g (7.57millimol (“mmol”) of ammonium 5-nitrotetrazolate in 30 milliliters(“mL”) of water. The solution was slowly added to a 30 mL solution of0.916 g (2.52 mmol) of [Fe(H₂O)₆](ClO₄)₂ or 0.502 g (2.52 mmol) ofFeCl₂●4H₂O with stirring. The orange and opaque solution was slowlybrought to reflux for 2 hours. The clear orange solution was then slowlycooled to 10° C. at the rate of 3° C./minute and maintained at thistemperature until the solution became colorless. Most of the motherliquor was decanted; the crystals were filtered, washed thoroughly withcold water, and air-dried.

Elemental analysis of the crystals, as set forth in TABLE 1, showed thecomposition corresponds to (NH₄)[Fe^(II)(NT)₃(H₂O)₃]. TABLE 1(NH₄)[Fe^(II)(NT)₃(H₂O)₃] CARBON HYDROGEN NITROGEN OXYGEN (%) (%) (%)(%) THEORETICAL 7.67 2.14 47.68 30.63 OBSERVED 7.82 2.08 45.20 30.45

The above-described synthesis yielded 95% (NH₄)[Fe^(II)(NT)₃(H₂O)₃].

The preparation procedure for (NH₄)₂[Fe^(II)(NT)₄(H₂O)₂] is similar tothat of (NH₄)[Fe^(II)(NT)₃(H₂O)₃] except that the stoichiometric amountof the desired salt of 5-nitrotetrazolate was used. Elemental analysisof the crystals, as set forth in TABLE 2, showed the compositioncorresponds to (NH₄)₂[Fe^(II)(NT)₄(H₂O)₂]. TABLE 2(NH₄)₂[Fe^(II)(NT)₄(H₂O)₂] CARBON HYDROGEN NITROGEN OXYGEN (%) (%) (%)(%) THEORETICAL 8.22 2.07 52.75 27.39 OBSERVED 8.29 1.79 48.96 27.62

The above-described synthesis yielded 96% (NH₄)₂[Fe^(II)(NT)₄(H₂O)₂].

The preparation procedures for (NH₄)₃[Fe^(II)(NT)₅(H₂O)] and(NH₄)₄[Fe^(II)(NT)₆] are similar to that of (NH₄)[Fe^(II)(NT)₃(H₂O)₃]except that absolute ethyl alcohol was the solvent and thestoichiometric amount of the desired salt of 5-nitrotetrazolate wasused. Elemental analysis of the crystals, as set forth in TABLES 3 and4, showed the compositions correspond to (NH₄)₃[Fe^(II)(NT)₅(H₂O)] and(NH₄)₄[Fe^(II)(NT)₆], respectively. TABLE 3 (NH₄)₃[Fe^(II)(NT)₅(H₂O)]CARBON HYDROGEN NITROGEN OXYGEN (%) (%) (%) (%) THEORETICAL 8.60 2.0256.17 25.21 OBSERVED 8.71 1.96 55.12 25.49

The above-described synthesis yielded 92% (NH₄)₃[Fe^(II)(NT)₅(H₂O)].TABLE 4 (NH₄)₄[Fe^(II)(NT)₆] CARBON HYDROGEN NITROGEN OXYGEN (%) (%) (%)(%) THEORETICAL 8.87 1.99 58.63 23.64 OBSERVED 8.96 1.89 56.42 23.51

The above-described synthesis yielded 94% (NH₄)₄[Fe^(II)(NT)₆].

Selected properties and sensitivities of ammonium5-nitrotetrazolato-N²-ferrate hierarchies are set forth in TABLE 5.TABLE 5 (NH₄)[Fe^(II)(NT)₃(H₂O)₃] (NH₄)₂[Fe^(II)(NT)₄(H₂O)₂](NH₄)₃[Fe^(II)(NT)₅(H₂O)] (NH₄)₄[Fe^(II)(NT)₆] DENSITY, g/cm³ 2.10 ±0.02 2.20 ± 0.03 2.34 ± 0.02 2.45 ± 0.02 THERMAL 261 255 253 252DECOMPOSITION TEMPERATURE, ° C. SPARK, J >0.36 >0.36 >0.36 >0.36FRICTION, kg 4.2 2.8 1.3 0.8 IMPACT, cm 15 12 10 8

EXAMPLE 2 Preparation of Na[Fe^(II)(NT)₃(H₂O)₃]

An iron compound was prepared in accordance with the reaction[Fe(H₂O)₆](ClO₄)₂+3 NaNT●2H₂O→Na[Fe(NT)₃(H₂O)₃]+2 NaClO₄ or FeCl₂●4H₂O+3NaNT●2H₂O→Na[Fe^(II)(NT)₃(H₂O)₃]+2 NaCl by mixing a solution of 1.00 g(5.78 mmol) of sodium 5-nitrotetrazolate dihydrate in 20 mL of water.The solution was slowly added to a 30 mL solution of 0.699 g (1.93 mmol)of [Fe(H₂O)₆](ClO₄)₂ or 0.383 g (1.93 mmol) of FeCl₂●4H₂O with stirring.The orange suspension was slowly brought to reflux for two hours. Theclear solution was then slowly cooled to 10° C. at the rate of 3°C./minute and maintained at this temperature until the solution becamecolorless. Most of the mother liquor was decanted; the crystals werefiltered, washed thoroughly with cold water, and air-dried.

Elemental analysis of the crystals, as set forth in TABLE 6, showed thecomposition corresponds to Na[Fe^(II)(NT)₃(H₂O)₃]. TABLE 6Na[Fe^(II)(NT)₃(H₂O)₃] CARBON HYDROGEN NITROGEN OXYGEN (%) (%) (%) (%)THEORETICAL 7.59 1.27 44.23 30.31 OBSERVED 7.72 1.34 42.86 30.66

The above-described synthesis yielded 94% Na[Fe^(II)(NT)₃(H₂O)₃].

The preparation procedure for Na₂[Fe^(II)(NT)₄(H₂O)₂] is similar to thatof Na[Fe^(II)(NT)₃(H₂O)₃] except that the stoichiometric amount of thedesired salt of 5-nitrotetrazolate was used. Elemental analysis of thecrystals, as set forth in TABLE 7, showed the composition corresponds toNa₂[Fe^(II)(NT)₄(H₂O)₂]. TABLE 7 Na₂[Fe^(II)(NT)₄(H₂O)₂] CARBON (%)HYDROGEN (%) NITROGEN (%) THEORETICAL 8.09 0.68 47.16 OBSERVED 8.22 0.7446.97

The above-described synthesis yielded 92% Na₂[Fe^(II)(NT)₄(H₂O)₂].

The preparation procedures for Na₃[Fe^(II)(NT)₅(H₂O)] andNa₄[Fe^(II)(NT)₆] are similar to that of Na[Fe^(II)(NT)₃(H₂O)₃] exceptthat absolute ethyl alcohol was the solvent and the stoichiometricamount of the desired salt of 5-nitrotetrazolate was used. Selectedproperties and sensitivities of sodium 5-nitrotetrazolato-N²-ferratehierarchies are set forth in TABLE 8. TABLE 8 Na[Fe^(II)(NT)₃(H₂O)₃]Na₂[Fe^(II)(NT)₄(H₂O)₂] Na₃[Fe^(II)(NT)₅(H₂O)] Na₄[Fe^(II)(NT)₆]DENSITY, g/cm³ 2.15 ± 0.03 2.25 ± 0.03 2.38 ± 0.03 2.47 ± 0.03 THERMAL255 250 252 250 DECOMPOSITION TEMPERATURE, ° C. SPARK,J >0.36 >0.36 >0.36 >0.36 FRICTION, g 36 20 17 12 IMPACT, cm 14 12 8 6

The preparation procedure for Na[Cu^(II)(NT)₃(H₂O)₃],Na₂[Cu^(II)(NT)₄(H₂O)₂], Na₃[Cu^(II)(NT)₅(H₂O)], and Na₄[Cu^(II)(NT)₆]are similar to those of Na[Fe^(II)(NT)₃(H₂O)₃], Na₂[Fe^(II)(NT)₄(H₂O)₂],Na₃[Fe^(II)(NT)₅(H₂O)], and Na₄[Fe^(II)(NT)₆], respectively, except thatthe stoichiometric amount of the copper metal hydrate salt was used.Similarly, the preparation procedure for (NH₄)[Cu^(II)(NT)₃(H₂O)₃],(NH₄)₂[Cu^(II)(NT)₄(H₂O)₂], (NH₄)₃[Cu^(II)(NT)₅(H₂O)], and(NH₄)₄[Cu^(II)(NT)₆] are similar to those of (NH₄)[Fe^(II)(NT)₃(H₂O)₃],(NH₄)₂[Fe^(II)(NT)₄(H₂O)₂], (NH₄)₃[Fe^(II)(NT)₅(H₂O)], and(NH₄)₄[Fe^(II)(NT)₆], respectively, except that the stoichiometricamount of the copper metal hydrate salt was used. Selected elementalanalysis of crystals from the above procedures, as set forth in TABLES 9and 10, showed the compositions correspond to Na₂[Cu^(II)(NT)₄(H₂O)₂]and (NH₄)₂[Cu^(II)(NT)₄(H₂O)₂], respectively. TABLE 9Na₂[Cu^(II)(NT)₄(H₂O)₂] CARBON (%) HYDROGEN (%) NITROGEN (%) THEORETICAL7.98 0.67 46.56 OBSERVED 8.02 0.72 46.55

The above-described synthesis yielded 94% Na₂[Cu^(II)(NT)₄(H₂O)₂]. TABLE10 (NH₄)₂[Cu^(II)(NT)₄(H₂O)₂] CARBON HYDROGEN NITROGEN OXYGEN (%) (%)(%) (%) THEORETICAL 8.12 2.04 52.07 27.03 OBSERVED 8.06 1.80 48.65 27.73

The above-described synthesis yielded 93% (NH₄)₂[Cu^(II)(NT)₄(H₂O)₂].

Selected properties and sensitivities of sodium and ammonia5-nitrotetrazolato-N²ferrate and cupric are set forth in TABLE 11. TABLE11 (NH₄)₂[Fe^(II)(NT)₄(H₂O)₂] Na₂[Fe^(II)(NT)₄(H₂O)₂](NH₄)₂[Cu^(II)(NT)₄(H₂O)₂] Na₂[Cu^(II)(NT)₄(H₂O)₂] DENSITY, g/cm³ 2.20 ±0.03 2.25 ± 0.03 2.06 ± 0.03 2.14 ± 0.02 THERMAL 255 250 265 259DECOMPOSITION TEMPERATURE, ° C. SPARK, J >0.36 >0.36 >0.36 >0.36FRICTION, g 2,800 20 500 40 IMPACT, cm 12 12 12 12

It is understood that the foregoing detailed description and examplesare merely illustrative and are not to be taken as limitations upon thescope of the invention, which is defined by the appended claims. Variouschanges and modifications to the disclosed embodiments will be apparentto those skilled in the art. Such changes and modifications, includingwithout limitation those relating to chemical structures, syntheses,formulations and/or methods of use of the invention, may be made withoutdeparting from the spirit and scope thereof.

All publications, patents, and patent applications cited in thisspecification are herein incorporated by reference as if each individualpublication or patent application were specifically and individuallyindicated to be incorporated by reference.

1. A compound of formula (cat)_(Y)[M^(II)(T)_(X)(H₂O)_(6-X)]_(Z) whereincat is a cation independently selected from the group consisting of (a)alkaline metals, (b) alkaline earth metals, (c) aliphatic and catenatedhigh-nitrogen cations, and (d) heterocyclic nitrogen cations; M^(II) isa metal in the oxidation state plus-two independently selected from thegroup consisting of (a) cobalt, (b) copper, (c) iron, (d) manganese, (e)nickel, and (f) zinc; T is the ligand 5-nitrotetrazolate (“NT”); and Xis an integer from 3 to 6; Y is an integer from 1 to 4; and Z is aninteger from 1 to
 2. 2. The compound of claim 1 wherein cat isindependently selected from the group consisting of lithium, sodium,pottasium, magnesium, calcium, strontium, triaminoguanidinium (TAG⁺),hydrazinium (Hz⁺), ammonium (Am⁺), and 1,5-diaminotetrazolium (DAT⁺),3,3-dinitroazetidinium (DNA⁺), 3,6-bis(guanidinium)-1,2,4,5-tetrazine(BGTz²⁺), 3,6-bis(nitroguanidinium)-1,2,4,5-tetrazine (BNGTz²⁺), and3,6-bis(hydrazinium)-1,2,4,5-tetrazine (BHzTz²⁺).
 3. The compound ofclaim 2 wherein cat is either sodium or ammonium.
 4. The compound ofclaim 3 wherein cat is sodium.
 5. The compound of claim 1 wherein X is6.
 6. The compound of claim 1 wherein M^(II) is iron.
 7. The compound ofclaim 1 wherein (cat)_(Y)[M^(II)(T)_(X)(H₂O)_(6-X)]_(Z) is(NH₄)[Fe^(II)(NT)₃(H₂O)₃].
 8. The compound of claim 1 wherein(cat)_(Y)[M^(II)(T)_(X)(H₂O)_(6-X)]_(Z) is (NH₄)₂[Fe^(II)(NT)₄(H₂O)₂].9. The compound of claim 1 wherein(cat)_(Y)[M^(II)(T)_(X)(H₂O)_(6-X)]_(Z) is (NH₄)₃[Fe^(II)(NT)₅(H₂O)].10. The compound of claim 1 wherein(cat)_(Y)[M^(II)(T)_(X)(H₂O)_(6-X)]_(Z) is (NH₄)₄[Fe^(II)(NT)₆].
 11. Thecompound of claim 1 wherein (cat)_(Y)[M^(II)(T)_(X)(H₂O)_(6-X)]_(Z) isNa[Fe^(II)(NT)₃(H₂O)₃].
 12. The compound of claim 1 wherein(cat)_(Y)[M^(II)(T)_(X)(H₂O)_(6-X)]_(Z) is Na₂[Fe^(II)(NT)₄(H₂O)₂]. 13.The compound of claim 1 wherein (cat)_(Y)[M^(II)(T)_(X)(H₂O)_(6-X)]_(Z)is Na₃[Fe^(II)(NT)₅(H₂O )].
 14. The compound of claim 1 wherein(cat)_(Y)[M^(II)(T)_(X)(H₂O)_(6-X)]_(Z) is Na₄[Fe^(II)(NT)₆].
 15. Thecompound of claim 1 wherein (cat)_(Y)[M^(II)(T)_(X)(H₂O)_(6-X)]_(Z) isNa[Cu^(II)(NT)₃(H₂O)₃].
 16. The compound of claim 1 wherein(cat)_(Y)[M^(II)(T)_(X)(H₂O)_(6-X)]_(Z) is Na₂[Cu^(II)(NT)₄(H₂O)₂]. 17.The compound of claim 1 wherein (cat)_(Y)[M^(II)(T)_(X)(H₂O)_(6-X)]_(Z)is Na₃[Cu^(II)(NT)₅(H₂O)].
 18. The compound of claim 1 wherein(cat)_(Y)[M^(II)(T)_(X)(H₂O)_(6-X)]_(Z) is Na₄[Cu^(II)(NT)₆].
 19. Thecompound of claim 1 wherein (cat)_(Y)[M^(II)(T)_(X)(H₂O)_(6-X)]_(Z) is(NH₄)₃[CU^(II)(NT)₅(H₂O)].
 20. The compound of claim 1 wherein(cat)_(Y)[M^(II)(T)_(X)(H₂O)_(6-X)]_(Z) is (NH₄)₄[Cu^(II)(NT)₆].